A fault tree is a graphical diagram that uses logic gates to model the various combinations of failures, faults, errors and normal events involved in causing a specified undesired event to occur. The fault tree analysis method is mainly used in the fields of safety engineering and reliability engineering to understand how systems can fail, to identify the best ways to reduce risk or to determine event rates of a safety accident. Fault tree analysis is used in the aerospace, nuclear power, chemical and process, pharmaceutical, petrochemical and other high-hazard industries. The fault tree model can be translated into a mathematical model in order to compute failure probabilities and system importance measures. A fault tree can model all aspects of a system, including hardware, software, human actions and the environment.

Benefits of Fault Trees Analysis- The fault tree explicitly shows all the different relationships that are necessary to result in the top event.- In constructing the fault tree, a thorough understanding is obtained of the logic and basic causes leading to the top event.- The fault tree is a tangible record of the systematic analysis of the logic and basic causes leading to the top event.- The fault tree provides a framework for thorough qualitative and quantitative evaluation of the top event.